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===Observations by amateur skywatchers===
In May 2010, an amateur astronomer claimed to spot the spacecraft from his home in [[Toronto]], Canada.<ref name=AU-May24>{{cite news |url=http://www.news.com.au/technology/amateur-astronomers-unravel-x37-b-orbit-say-likely-use-for-deploying-spy-satellites/story-e6frfro0-1225870574214 |title=Amateur astronomers unravel X37-B orbit, say likely use for deploying spy satellites |work=News.com.au |date=24 May 2010}}</ref> Shortly after the initial observation, several more detailed observations were made by amateur skywatchers from around the world, who reported the spacecraft to have an almost circular {{convert|401|to|422|km|mi|abbr=on}} low Earth orbit with an inclination of 40°.<ref name=Space-May22>{{cite news |url=http://www.space.com/news/secret-x-37-b-space-plane-spotted-by-amateur-astronomers-100522.html |title=Secret X-37B spaceplane spotted by amateur skywatchers |work=Space.com |first=Leonard |last=David |date=22 May 2010}}</ref> The group believed in their calculations and observations with a high degree of confidence.<ref name=Space-May22/> The spacecraft's [[ground pathtrack]] was observed to repeat every four days, which was considered indicative for a possible imaging reconnaissance mission profile.<ref name=Space-May22/><ref name="NYT20100522">{{cite news |url=http://www.nytimes.com/2010/05/23/science/space/23secret.html?pagewanted=all |title=Surveillance Is Suspected as Spacecraft's Main Role |work=[[The New York Times]] |first=William J. |last=Broad |authorlink=William Broad |date=21 May 2010 |accessdate=23 May 2010}}</ref>
 
For two weeks, starting on 29 July, the amateur skywatchers were unable to find the spacecraft in the locations they had predicted, leading them to believe it had suddenly changed its course.<ref name=AU-Aug24>{{cite news |url=http://www.news.com.au/technology/us-militarys-top-secret-x-37b-shuttle-disappears-for-two-weeks-changes-orbit/story-e6frfro0-1225909738276 |title=US military's top secret X-37B shuttle 'disappears' for two weeks, changes orbit |work=News.com.au |first=Peter |last=Farquhar |date=25 August 2010}}</ref> During the mission, the vehicle was observed to change its orbit multiple times, with a total [[delta-v]] of the first four orbit changes amounting to {{convert|102| m/s|abbr=on}}. A common characteristic of all the orbits was that the [[ground track]] nearly repeated every few days.<ref name="AU-Aug24"/><ref name="seesat_Nov-2010_0287.html"/> By 12 November 2010, the orbit had been lowered to {{convert|281|by|292|km|mi|abbr=on}} with the ground track now repeating every three days (47 orbits).<ref name="seesat_Nov-2010_0287.html">{{cite web |url=http://www.satobs.org/seesat/Nov-2010/0287.html|title=Updated X-37B OTV 1-1 elements|work=SatObs.org |first=Ted|last=Molczan|accessdate=25 November 2010|date=25 November 2010}}</ref>

Revision as of 13:26, 13 May 2015

USA-212
OTV-1 during encapsulation prior to maiden launch
Mission typeDemonstration
OperatorU.S. Air Force/DARPA
COSPAR ID2010-015A[1]
SATCAT no.36514
Mission duration224 days, 9 hours, 24 minutes
Spacecraft properties
Spacecraft typeBoeing X-37B
ManufacturerBoeing
Launch mass5,400 kg (11,900 lb)[2]
PowerDeployable solar array, batteries[2]
Start of mission
Launch date22 April 2010, 23:52:00 (2010-04-22UTC23:52Z) UTC[3]
RocketAtlas V 501[2]
Launch siteSLC-41, Cape Canaveral
ContractorUnited Launch Alliance
End of mission
Landing date3 December 2010, 09:16:00 (2010-12-03UTC09:17Z) UTC[4]
Landing siteVandenberg, Runway 12
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Semi-major axis6,598 km (4,100 mi)[5]
Eccentricity0.0006[5]
Perigee altitude279 km (173 mi)[5]
Apogee altitude287 km (178 mi)[5]
Inclination39.9979°[5]
Period88.9 min[5]
Mean motion15.97[5]
Epoch29 November 2010, 04:26:19 UTC[5]

USA-212[1] was the first flight of the Boeing X-37B Orbital Test Vehicle 1 (X-37B OTV-1), an American unmanned robotic vertical-takeoff, horizontal-landing (VTHL) spaceplane. It was launched aboard an Atlas V rocket from Cape Canaveral on 22 April 2010, and operated in low Earth orbit. Its designation is part of the USA series.

The spaceplane is operated by the United States Air Force, which has not revealed the specific identity of the spaceship's payload for the mission. The Air Force has stated only that the spacecraft would "demonstrate various experiments and allow satellite sensors, subsystems, components, and associated technology to be transported into space and back."[6]

Launch

USA-212 was launched on an Atlas V 501 rocket, tail number AV-012, from Space Launch Complex 41 at the Cape Canaveral Air Force Station in Florida.[7][8] The launch, which was conducted by United Launch Alliance, occurred at 23:52 UTC on 22 April 2010, placing the spacecraft into low Earth orbit for testing.[9]

The X-37B spacecraft was originally intended to be deployed from the payload bay of a NASA Space Shuttle, but following the Columbia accident, it was transferred to a Delta II 7920. It was subsequently transferred to the Atlas V following concerns over the X-37B's aerodynamic properties during launch.[2]

The launch was the first flight of the Atlas V 501 configuration,[10] and the first in four years to use a 5.4-meter (18 ft) payload fairing.[10][11] Prior to the installation of the spacecraft, the Atlas rocket was moved to the launch pad and performed a wet dress rehearsal on 2 April 2010.[12] It was returned to the Vertical Integration Facility the next day for final assembly.[13] The X-37 arrived at the VIF on 8 April. On 9 April, a 24-hour delay was announced. It subsequently slipped a further 24 hours after the landing of Space Shuttle Discovery on Mission STS-131 was delayed, as the Eastern Range could not have been reconfigured quickly enough to accommodate both events on the same day.[13] After a series of delays, it was set for 19 April 2010. On 21 April, the Atlas was rolled back out to the launch pad for launch.[13] The launch window on 22 April opened at 23:52 UTC, and closed at 00:01 on 23 April.

Mission

Most of the mission parameters for the USA-212 flight have not been disclosed.[8] The vehicle is capable of being on-orbit for up to 270 days. The Air Force stated the mission time would depend on progress of the craft's experiments during orbit.[14] Mission control was handled by the 3d Space Experimentation Squadron, 21st Space Wing, of the Air Force Space Command in Colorado Springs.[15]

Observations by amateur skywatchers

In May 2010, an amateur astronomer claimed to spot the spacecraft from his home in Toronto, Canada.[16] Shortly after the initial observation, several more detailed observations were made by amateur skywatchers from around the world, who reported the spacecraft to have an almost circular 401 to 422 km (249 to 262 mi) low Earth orbit with an inclination of 40°.[17] The group believed in their calculations and observations with a high degree of confidence.[17] The spacecraft's ground track was observed to repeat every four days, which was considered indicative for a possible imaging reconnaissance mission profile.[17][18]

For two weeks, starting on 29 July, the amateur skywatchers were unable to find the spacecraft in the locations they had predicted, leading them to believe it had suddenly changed its course.[19] During the mission, the vehicle was observed to change its orbit multiple times, with a total delta-v of the first four orbit changes amounting to 102 m/s (330 ft/s). A common characteristic of all the orbits was that the ground track nearly repeated every few days.[19][20] By 12 November 2010, the orbit had been lowered to 281 by 292 km (175 by 181 mi) with the ground track now repeating every three days (47 orbits).[20]

Altitude and ground track resonance history

Based on data collected by amateur observers, the following orbital characteristics were calculated by amateur skywatcher Ted Molczan.

Time period Periapsis
(AMSL) 		Apoapsis
(AMSL) 		Resonance
(orbits:days)
2010 Apr 22 – Aug 9[21] 403 km (250 mi)[21] 420 km (260 mi)[21] 61:4[18]
2010 Aug 9 – Oct 6[22] 433 km (269 mi)[21] 444 km (276 mi)[21] 91:6
2010 Oct 6 – Nov 1[4] 390 km (240 mi) 395 km (245 mi) 46:3
2010 Nov 1 – Nov 12[4] 315 km (196 mi) 328 km (204 mi) 31:2
2010 Nov 12 – Dec 3 281 km (175 mi) 292 km (181 mi) 47:3

Landing

Infrared view of OTV1 after landing

After completing its mission, the X-37B was deorbited, entered the atmosphere, and landed at Vandenberg Air Force Base on 3 December 2010.[23]

The X-37B is the second reusable spacecraft to perform an automated landing after returning from orbit, the first being the Soviet Buran spacecraft in 1988.[24]

Hypothetical mission components

As the mission of USA-212 and the X-37B program are classified, public commentary on the program is speculation. James Oberg speculated that the concurrent launch of Air Force's Hypersonic Technology Vehicle HTV-2 was related to the mission. Part of an X-37B's mission profile might involve a simulated enemy attack, which the X-37B should be able to detect and autonomously counteract.[25] HTV-2 was launched at 23:00 UTC on 22 April 2010, i.e., 52 minutes ahead of X-37B, from Vandenberg Air Force Base in California,[26] on a suborbital trajectory supposed to last less than 25 min.[27] The mission failed and was aborted nine minutes after launch.[28][29]

William Scott, coauthor of the techno-novel Counterspace: The Next Hours of World War III and former Rocky Mountain Bureau Chief for Aviation Week & Space Technology magazine believes that with X-37B, the Air Force might test weapon delivery from a space plane in low Earth orbit. He mentions Rods from God as a possible scenario.[30] This hypothesis aligns with speculation that the launch of USA-212 marks the beginning of military operations in space.[31]

See also

References

  1. ^ a b "X-37B - Satellite Information". Heavens Above. Retrieved 10 July 2013.
  2. ^ a b c d Krebs, Gunter D. "X-37B OTV 1, 2, 3". Gunter's Space Page. Retrieved 10 July 2013.
  3. ^ "OTV 1: Launch information". National Space Science Data Center via NASA.gov. Retrieved 10 July 2013. {{cite web}}: Italic or bold markup not allowed in: |work= (help)
  4. ^ a b c Clark, Stephen (30 November 2010). "Secret mini-shuttle due for landing as soon as Friday". Spaceflight Now. Retrieved 5 December 2010.
  5. ^ a b c d e f g h "X-37B - Orbit". Heavens Above. 29 November 2010. Retrieved 10 July 2013.
  6. ^ Lubold, Gordon (20 April 2010). "Air Force To Launch X-37 Space Plane: Precursor To War In Orbit?". The Christian Science Monitor. Retrieved 23 April 2010.
  7. ^ Leonard, David (22 October 2009). "Air Force's Secretive Space Plane Nears Maiden Voyage". Space.com.
  8. ^ a b Clark, Stephen (25 February 2010). "Air Force X-37B spaceplane arrives in Florida for launch". Spaceflight Now. Retrieved 3 March 2010.
  9. ^ Clark, Stephen (22 April 2010). "Atlas rocket delivers Air Force spaceplane to orbit". Spaceflight Now. Retrieved 23 April 2010.
  10. ^ a b "Air Force officials launch Atlas V carrying X-37B Orbital Test Vehicle". AF.mil. U.S. Air Force. 23 April 2010. Archived from the original on 27 May 2012. Retrieved 23 April 2010.
  11. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 23 April 2010.
  12. ^ Clark, Stephen (2 April 2010). "Air Force spaceplane is an odd bird with a twisted past". Spaceflight Now. Retrieved 23 April 2010.
  13. ^ a b c Ray, Justin (23 April 2010). "Mission Status Center (OTV-1)". Spaceflight Now. Retrieved 23 April 2010.
  14. ^ Klotz, Irene (24 April 2010). "U.S. Air Force X-37B Launched". Aviation Week.
  15. ^ "Air Force Bloggers Roundtable: Air Force set to launch first X-37B Orbital Test Vehicle". DODlive.mil. U.S. Department of Defense. 20 April 2010. Retrieved 23 April 2010.
  16. ^ "Amateur astronomers unravel X37-B orbit, say likely use for deploying spy satellites". News.com.au. 24 May 2010.
  17. ^ a b c David, Leonard (22 May 2010). "Secret X-37B spaceplane spotted by amateur skywatchers". Space.com.
  18. ^ a b Broad, William J. (21 May 2010). "Surveillance Is Suspected as Spacecraft's Main Role". The New York Times. Retrieved 23 May 2010.
  19. ^ a b Farquhar, Peter (25 August 2010). "US military's top secret X-37B shuttle 'disappears' for two weeks, changes orbit". News.com.au.
  20. ^ a b Molczan, Ted (25 November 2010). "Updated X-37B OTV 1-1 elements". SatObs.org. Retrieved 25 November 2010.
  21. ^ a b c d e David, Leonard (24 August 2010). "Secret X-37B space plane has changed orbit". MSNBC. Retrieved 5 December 2010.
  22. ^ Wethington, Nicholos (11 October 2010). "'Secret' X-37B Space Plane Disappears Again". Universe Today. Retrieved 5 December 2010.
  23. ^ Clark, Stephen (3 December 2010). "Home again: U.S. military space plane returns to Earth". Spaceflight Now.
  24. ^ Chertok, Boris E. (2005). Siddiqi, Asif A. (ed.). Rockets and People (PDF). NASA History Series. Vol. 1. National Aeronautics and Space Administration. p. 179. SP-2005-4110.
  25. ^ Oberg, James (31 March 2010). "U.S. Air Force Launches Secret Flying Twinkie: Military's new space plane tests unnamed powers". IEEE Spectrum. Retrieved 25 April 2010.
  26. ^ Clark, Stephen (23 April 2010). "New Minotaur rocket launches on suborbital flight". Spaceflight Now. Retrieved 25 April 2010.
  27. ^ Little, Geoffrey (1 September 2007). "Mach 20 or Bust". Air & Space.
  28. ^ Jones, Johanna (23 April 2010). "Falcon HTV-2 Launch Tests Hypersonic Vehicle Flight Capabilities" (PDF) (Press release). DARPA. Retrieved 5 December 2010.
  29. ^ "DARPA Concludes Review of Falcon HTV-2 Flight Anomaly" (PDF). DARPA (Press release). 16 November 2010. Retrieved 5 December 2010.
  30. ^ David, Leonard (12 April 2010). "Air Force's Mystery X-37B Space Plane Fuels Speculation". Space.com.
  31. ^ Starr, Barbara (23 April 2010). Mystery military space plane. CNN.com (Video).
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